Open AccessFunctional analyses of cellulose synthase genes in flax ( Linum usitatissimum ) by virus‐induced gene silencing
Author(s) -
Chantreau Maxime,
Chabbert Brigitte,
Billiard Sylvain,
Hawkins Simon,
Neutelings Godfrey
Publication year - 2015
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/pbi.12350
Subject(s) - linum , biology , bast fibre , gene , gene silencing , gene family , cell wall , cellulose , secondary cell wall , transcriptome , botany , genome , genetics , gene expression , biochemistry
Summary Flax ( Linum usitatissimum ) bast fibres are located in the stem cortex where they play an important role in mechanical support. They contain high amounts of cellulose and so are used for linen textiles and in the composite industry. In this study, we screened the annotated flax genome and identified 14 distinct cellulose synthase ( CESA ) genes using orthologous sequences previously identified. Transcriptomics of ‘primary cell wall’ and ‘secondary cell wall’ flax CESA genes showed that some were preferentially expressed in different organs and stem tissues providing clues as to their biological role(s) in planta . The development for the first time in flax of a virus‐induced gene silencing ( VIGS ) approach was used to functionally evaluate the biological role of different CESA genes in stem tissues. Quantification of transcript accumulation showed that in many cases, silencing not only affected targeted CESA clades, but also had an impact on other CESA genes. Whatever the targeted clade, inactivation by VIGS affected plant growth. In contrast, only clade 1‐ and clade 6‐targeted plants showed modifications in outer‐stem tissue organization and secondary cell wall formation. In these plants, bast fibre number and structure were severely impacted, suggesting that the targeted genes may play an important role in the establishment of the fibre cell wall. Our results provide new fundamental information about cellulose biosynthesis in flax that should facilitate future plant improvement/engineering.